Christian Pulisic’s away goal in the 1-1 first-leg draw in Madrid gave Chelsea the advantage heading into the second leg, and Werner’s first-half header put them on course to a second European Cup final in two years for Thomas Tuchel, whose PSG were beaten by Bayern Munich last season.
Zinedine Zidane’s Real could not deal with Chelsea’s quick counter-attacking, and the only reason the Spanish giants were not humiliated in west London was the astonishing amount of second-half chances the Blues missed.
But Mount made sure of the win with a goal late in the second half.
Tuchel was tasked by Roman Abramovich with delivering silverware immediately after replacing Frank Lampard – and though few gave him a realistic chance when he arrived, the German coach is now one game away from the ultimate prize in European club football.
Werner thought he had given Chelsea the lead early on after tucking home a Ben Chilwell cross from the left flank, but the offside flag went up – and replays showed the German forward had no need to be off.
Thankfully for Chelsea, Edouard Mendy was in superb form as he made a world-class save to deny Karim Benzema by tipping wide a 20-yard fizzing effort.
Werner soon made amends for Chelsea, and could not have wished for an easier chance. N’Golo Kante, who was inspirational in the first leg, led the charge in the middle once again, slipping Kai Havertz in on the left.
Havertz lofted the ball over Thibaut Courtois but hit the bar, though the ball fell kindly for Werner to head in an empty net from two yards out.
Mendy then made another impressive save from a Benzema header as Chelsea went into the interval 1-0 up on the night, and 2-1 on aggregate.
Chelsea wasted a number of chances in the first leg, and were guilty of the same again early in the second half.
Havertz hit the bar with a header; Mason Mount blazed over when clean through; Havertz then missed a gilt-edged one-on-one chance which drew a great save from Courtois, and the Real keeper then denied Kante from point-blank range in another one-on-one.
Thiago Silva also had two decent headed chances, but Chelsea were not made to rue those misses given Real struggled to create many chances of note. Eden Hazard forced a smart low stop from Mendy, but was otherwise quiet on his return to the Bridge as he watched his former club reach the Champions League final when Mount sealed victory.